QKeySequence::PreviousChild not working

#include <QtGui>

class TabWidget : public QTabWidget
{
	Q_OBJECT
public:
	TabWidget()
	{
		firstTab = new QWidget(this);
		secondTab = new QWidget(this);

		addTab(firstTab, "First Tab");
		addTab(secondTab, "Second Tab");

		secondAction = new QAction(this);
		secondAction->setShortcut(QKeySequence::PreviousChild);


		QAction *firstAction = new QAction(this);
		firstAction->setShortcut(QKeySequence::NextChild);

		addAction(secondAction);
		addAction(firstAction);

		connect(firstAction, SIGNAL(triggered(bool)), this, SLOT(nextTabPageTriggered()));
		connect(secondAction, SIGNAL(triggered(bool)), this, SLOT(previousTabPageTriggered()));
	}

	public slots:
		void nextTabPageTriggered()
		{
			qDebug() << "NEXT";
		}

		void previousTabPageTriggered()
		{
			qDebug() << "PREVIOUS";
		}

private:
	QWidget *firstTab;
	QWidget *secondTab;
	QAction *secondAction;
};

#include "main.moc"

int main(int argc, char** argv)
{
	QApplication app(argc, argv);
	TabWidget window;
	window.show();
	return app.exec();

}